Energy futureWater consumption by thermoelectric plants to grow 35.7%

Published 10 December 2007

Water shortages loom as one of the major problems in the next two decades for both developed and developing countries; it does not help that water consumption by thermoelectric power plants will increase by nearly 40% during this period — and even more if carbon capturing technologies are adopted

The Office of Fossil Energy’s National Energy Technology Laboratory (NETL) of the U.S. Department of Energy (DOE) has released a 2007 update to its groundbreaking study, “Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements”. The updated analysis increases understanding of regional and national water needs and usage in the power industry, and provides ideas for research and development aimed at water-use reduction. New in this year’s report is a response to heightened concerns over atmospheric carbon dioxide. The report examines the possibility that future policies to combat climate change may result in the addition of carbon capture technologies to many coal-fired power plants by 2030. Since these technologies require additional water, the 2007 report includes case study scenarios that predict how much water may be needed by power plants when carbon capture technology is installed.

Water has become an important issue since economic development depends on the availability of fresh water. Public water systems, agriculture, power generation, and other industries all compete for limited regional water supplies. The power industry is only responsible for around 3 percent of the freshwater consumed in the United States, it accounts for nearly 40 percent of withdrawals. Recently, construction of new power plants had to be shelved because water-use permits could not be obtained, and insufficient supplies of water due to extended drought and population growth have resulted in a reduction in plant output in several regions of the United States. The new analysis examines five separate future cases using NETL’s Water Use Projections Model and projections for regional electricity demand and capacity from the Energy Information Administration’s Annual Energy Outlook 2007. As is the case with the 2006 report, the new report predicts fresh water withdrawal and consumption by thermoelectric plants regionally and nationally, by decade, through 2030. Four of the five cases presented in the 2007 report predict that, on a national basis, water withdrawals by the power industry will decrease. On average, water withdrawals by thermoelectric plants are projected to decline more than 3.5 percent. Water consumption by thermoelectric plants, however, is predicted to grow. By 2030 the average expected increase is 35.7 percent. On a regional basis, water withdrawal projections for thermoelectric plants range from a 42 percent increase in the Northwest, to a 24 percent decline in the Rocky Mountain and southwest desert region. Fresh water consumption will increase in all regions, showing the largest gains in areas where the population is expected to increase the most — New York: 396 percent, California: 274 percent, and Florida: 250 percent. When carbon capture technologies are added to coal-fired power plants, water withdrawal nationally is projected to increase from 4.1 to 6.0 billion gallons per day, with an average projected increase of water withdrawal of seven percent. Water consumption is expected to rise from 2.2 to 4.3 billion gallons per day. The average increase of water consumption from all cases with carbon capture is 90 percent.

NETL is working to reduce water usage by fossil-fuel-fired power plants through their Innovations for Existing Plants program. The program’s goals are to enhance the efficiency and environmental performance of existing coal-fired power plants and to apply novel concepts to advanced power systems. NETL recently joined with Sandia National Laboratories through a memorandum of understanding to advance research, development, demonstration, and, ultimately, the commercialization of technologies to reduce freshwater usage related to thermoelectric power production while minimizing its impact on water quality.